class Car {
    // 属性
    private String make;
    private String model;
    private int year;
    private String color;
    private int mileage;

    // 构造方法
    public Car(String make, String model, int year, String color, int mileage) {
        this.make = make;
        this.model = model;
        this.year = year;
        this.color = color;
        this.mileage = mileage;
    }

    public Car(String make, String model, int year) {
        this.make = make;
        this.model = model;
        this.year = year;
        this.color = "Unknown";
        this.mileage = 0;
    }

    // 方法
    public void startEngine() {
        System.out.println(make + " " + model + "'s engine is started.");
    }

    public void drive(int distance) {
        mileage += distance;
        System.out.println("Driving " + distance + " miles...");
        System.out.println("Current mileage: " + mileage + " miles.");
    }

    public void displayInfo() {
        System.out.println("Make: " + make);
        System.out.println("Model: " + model);
        System.out.println("Year: " + year);
        System.out.println("Color: " + color);
        System.out.println("Mileage: " + mileage + " miles.");
    }
}